Method and apparatus for side grinding flats on a carding machine



P 1970 A. R. BECHTEL, JR.. ET AL 3,

METHOD AND APPARATUS FOR-SIDE GRINDING FLATS V ON A CARDING MACHINEFiled March 5. 1968 4 Sheets-Sheet 1 I NVENTORS ALFRED R. BECHTEL, JRv I26 v LUTHER W. BRlDGES, JR.

NORMAN F. CHANDLER L 1? J A'ITORNEYS I S ept. 15, 1970 A. RBECHTEL,JR... ET AL 3, 8,

METHOD AND'APPARATUS FOR SIDE GRINDING FLATS ON A CARDING MACHINE FiledMarch 5, 1968 4 Sheets-$heet 2 Sept. 15, 1970 G- JR" ET AL 3,528,136

METHOD AND APPARATUS FOR SIDE GRINDING FLATS ON A CARDING MACHINE FiledMarch 5, 1968 4 Sheets-Sheet a AL 3,528,136 IDE GRINDING FLATS wmcnms p1970 A. R. BECHTEL, JR.

METHOD AND APPARATUS FOR 5 ON A CARDING 4 Sheets-Sheet 1 Filed March 5,1968 United States Patent "ice 3,528,136 METHOD AND APPARATUS FOR SIDEGRINDING FLATS ON A CARDING MACHINE Alfred R. Bechtel, Jr., Portsmouth,R.I., and Luther W. Bridges, Jr., and Norman F. Chandler, Greenvllle,S.C., assignors to Ashworth Bros. Inc., Fall River, Mass, a corporationof Massachusetts Continuation-impart of application Ser. No. 649,206,June 27, 1967. This application Mar. 5, 1968', Ser. No. 717,062

Int. Cl. D01g 15/08 US. Cl. 19-402 15 Claims ABSTRACT OF THE DISCLOSUREA method and apparatus for the side grinding of the wire teeth of cardflats as the flats are cycled about their drive path on a cardingmachine.

RELATED APPLICATION This application is a continuation-in-part ofapplicants co-pending application, Ser. No. 649,206 filed June 27, 1967,now abandoned, entitled Method and Apparatus for Side Grinding Flats ona Carding Machine.

BACKGROUND OF THE INVENTION This invention relates to the side grindingor reneedling of carding flats and more particularly to a new andimproved method and apparatus for side grinding of carding flats as theflats are driven in their operative position on a carding machine.

In the field of fiber alignment by a carding operation, the nep count ofthe produced yarn bears a direct relation to the condition of the wireteeth on the carding flats. It is desirable to maintain the dimension ofthe top of the wire teeth, in a direction transverse to the movement ofthe flats, in the range between .003 inch and .004 inch to therebyprovide suflicient space between adjacent rows of wire teeth such thatthe fiber may be properly aligned. In addition, the abrasive action ofemery or the like improves the fiber gripping ability of teeth byproviding the sides of the teeth near the point with microscopiccorrugations and jagged points or spikes. Abrasion by the fiber duringthe carding operation tends to polish the sides of the teeth and dullthe points thereby decreasing the spacing between the points of adjacentrows and removing the microscopic corrugations and points. Thispolishing action thereby reduces the ability of the teeth to grip andalign the fibers.

Maintenance of the Wire teeth of the carding flats in the propercondition has produced considerable difliculty in the art. In prior artside grinding operations, it is necessary to remove the flats from thecarding equipment and place the flats in machines specifically designedfor side grinding of the teeth. This prior art side grinding operationis expensive, in terms of man hours expended, down time for the cardingmachinery and in capital outlay for the purchase of such specialgrinding machines. As a result of these maintenance expenses, a millwill often prolong the use of a set of flats without reneedling, therebyseriously affecting the quality of the yarn produced.

SUMMARY OF THE INVENTION This invention is employed on a carding machineof the type employing a set of carding flats having on their outersurfaces card clothing comprised of a plurality of gen erally parallel,spaced rows of wire teeth, said flats being driven in cooperativerelation with a carding cylinder in a direction parallel to the rows.The width of the flats and the lengths of the rows of teeth are such asto leave open 3,528,136 Patented Sept. 15, 1970 spaces between the endsof the rows of teeth on adjoining flats. This invention includes amethod and apparatus for side grinding or reneedling of the teeth onsaid flats as the flats are driven in their operative position on thecarding machine. The flats may be driven in the conventional mannerduring the operation of the carding machine, or by a second drivingmeans employed for driving the set of carding flats at an increasedspeed when the remainder of the. carding machine is not in operation.

This invention includes a side grinding assembly mounted in cooperativerelation to the card flats. The side grinding assembly includes agrinding head having a plurality of grinding discs each definingabrasive surfaces with a portion of each of said discs being disposedbetween the rows of teeth on the carding flats. The discs are rotatablydriven through a plane defined by the tops of said teeth causing saidabrasive surfaces to etfect a side grinding operation on the teeth. Thegrinding head is operatively mounted on means for reciprocally movingsaid grinding head across the set of flats transversely of said rows ofteeth. This traversing movement is at a speed sufficiently slow relativeto the speed of movement of the flats themselves, such that the abrasivesurface of each of the discs bears against the moving teeth in aparticular row on a particaular flat and substantially never passesacross that row on that particular flat but passes from one row toanother only in the open spaces between the teeth on adjoining flats. Inthis manner, the discs are driven back and forth across the set of flatsproviding a side grinding operation on each side of each row of teeth onthe flats without damaging the teeth by passing across the tops thereof.This side grinding may be conducted while the flats are mounted on thecard either during the carding operation or when the machine has beenstopped and the flats are driven separately.

It is an object of this invention to alleviate the aforementioneddifiiculties in the prior art by providing a new and improved method andapparatus for efliciently and effectively accomplishing the sidegrinding of the card clothing on carding flats as the flats are mountedin their operative position on the carding machine. This inventionthereby effectively reduces the expenses attendant the maintenance ofcarding flats, including either an elimination or reduction of the downtime for the carding machinery.

It is a further object of this invention to provide such a method andapparatus whereby the side grinding of the teeth on the carding flatsmay be accomplished during the carding operation with the carding flatsbeing driven in cooperative relation with the carding cylinder.

It is a further object of this invention to provide such a method andapparatus whereby the driving means for the carding machinery may bedisconnected from the carding flats and a second driving means coupledthereto for driving the flats while still mounted on the card at anincreased rate of speed when the carding machine is not in operation tothereby expedite the side grinding of the teeth of the carding flats.

It is also an object of this invention to provide such a method andapparatus whereby the teeth on the carding flats can be frequentlyground to maintain said teeth at the proper dimension and in the propercondition to appreciably reduce the nep count providing a higher qualityyarn at a reduced production cost.

It is a further object of this invention to provide such a method andapparatus employing a grinding head movable transversely of thedirection of movement of the carding flats at a speed related to thespeed of movement of the carding flats whereby the teeth of the cardingflats may be side ground to the proper degree without damaging theindividual teet hand avoiding the creation of a 3 patterned effect inthe teeth of the carding flats. A patterned effect of this nature causesthe traversing grinding head to continually follow the same course orpath in traversing the flats, thereby side grinding substantially thesame teeth on each traverse thereby missing many of the teeth.

Other objects and advantages of this invention will become apparent fromthe following description taken in connection with the accompanyingdrawings, wherein embodiments of this invention are set forth by 'way ofillustration and example.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational viewdiagrammatically showing a carding machine with a set of revolving cardflats in cooperative relation to a carding cylinder and a side grindingassembly in cooperative relation with the carding flats.

FIG. 2 is a sectional view taken on line 22 of FIG. 1, showing the sidegrinding assembly with the grinding head disposed in grinding relationto plurality of rows of wires on a carding flat.

FIG. 3 is a sectional view through the grinding head showing the threadfollower on the grinding head in engagement with the cross thread of thescrew shaft.

FIG. 4 is a fragmentary sectional view taken on line 44 of FIG. 2illustrating one of the adjustable brackets for mounting the grindingassembly directly to the carding machine.

FIG. 5 is an end elevational view of the gear box showing the back platewith the screw shaft extending therethrough and having an end portionadapted to receive a crank or other means for manual positioning of thegrinding head.

FIG. 6 is a sectional view taken through a single carding flat showingthe relation of the abrasive disc of the grinding head to a row of wireson the carding flat.

FIG. 7 is comprised of FIGS. 7a, 7b, 7c and 7d, all illustrating thecooperative action between the wires on the carding flat and theflexible abrasive disc on the grinding head. FIG. 7a shows the abrasivedisc disposed between adjacent rows of wire teeth on the carding fiat ina position for effecting a side grinding action on each of said rows.FIG. 7b illustrates the bending of the wires in that row as the pressureand abrasive action is increased due to the displacement of the grindinghead. In FIG. 7c, the grinding disc has passed to the next row in asubsequent flat. FIG. 7d is a schematic plan view of the disc movementillustrated in FIGS. 7a, 7b, and 70.

FIG. 8 is a perspective view diagramatically showing the geartransmission system employed between the driven drum and the screwshaft.

FIG. 9 is a sectional view through the gear box of the grindingassembly.

FIG. 10 is a sectional view taken on line 1010 of FIG. 9 showing thegear transmission system substantially in an end elevational view.

FIG. 11 is a sectional view taken on line 1111 of FIG. 10 showing ameans for uncoupling the gear transmission system.

FIG. 12 is a sectional view taken on line 1212 of FIG. 10 showing themounting of one of the idler gears.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, thereference numeral 1 broadly designates a carding machine embodying thefeatures of this invention. The carding machine 1 includes a licker-inroller 2 which feeds a fibrous material from a supply 4 through feedrollers 6 to a carding cylinder 8. The carding cylinder 8 is disposed incooperative relation with a revolving flat card 10 for aligning thefibers and moving the fibrous material to a doifer roll 12 from whichthe material is removed from the carding machine by a dolfing take oifdevice 14. The flat card 10, as illustrated, is conventional in nature,being comprised of a series of chain mounted flats 16 (FIGS. 6 and 7).The flats 16 each have on their outer surfaces card clothing,illustrated herein, as wire teeth or bent wires 18. As illustrated inFIG. 7d, the wires 18 of the flats 16 are disposed in a series ofparallel, spaced rows extending generally in the direction of movementof the flat card 10. The rows of wires 18 defining passagewaystherebetween.

Side grinding assembly Referring to FIGS. 1 and 2, a side grindingassembly 2Q is illustrated mounted directly on the carding machine 1 incooperative relation with the flat card 10 for side grinding orreneedling of the wires 18. The side grinding assembly 20 is comprisedof a grinding head 22, a drum or tube 24, a cross-threaded screw shaft26 and a speed transmission system 34. The grinding head 22 isoperatively mounted on the drum 24 for rotation with said drum 24 and isreciprocally slidable longitudinally of the drum 24 by the cooperativeaction of the cross-threaded screw shaft 26. Referring to FIGS. 2 and 3,the drum 24 contains a keyway or slot 28 through which a thread follower29 on the grinding head 22 extends for cooperative engagement in thecross thread of the screw shaft 26. The speed at which the grinding head22 traverses the flats 16 is directly related to the speed differentialbetween the drum 24 and the shaft 26. A decrease in speed differentialdecreases the rate of traverse of the grinding head 22 to the pointwhere zero speed differential causes the grinding head to remain in astationary position.

As illustrated in FIGS. 1 and 2, the drum 24 and grinding head 22 aredriven at a desired speed by a motor 30. The motor 30 is preferablysupported by a bracket 31 suitably mounted on the carding machine 1. Asillustrated, the motor 30 is connected to the drum 24 by a chain drivesystem 32. The drum 24 and screw shaft 26 are interconnected by a speedtransmission assembly 34 which provides a slight positive or negativespeed differential between the drum 24 and the screw shaft 26.

Referring to FIGS. 2 and 3, the grinding head 22 is comprised of a bodymember 35 for retaining a plurality of abrasive disc members 37 inposition. The abrasive disc members 37 may be of flexible rubber boundedby emery or the like defining a pair of opposed abrasive surfaces 39. Asillustrated in FIG. 7, the peripheral edge portion 33 of the discs 37are tapered providing an abrasive surface for hearing against the sidesof the wires 18 disposed at approximately 30 degrees to the wires 18,whereby the tops of the wires may be suitably shaped by side grinding.This tapered edge of the disc both facilitates entry between the rows ofteeth and the grinding of a taper on the teeth.

Referring to FIG. 4, an adjustable bracket 36 for retaining the grindingassembly 20 in relation to the bent wires 18 includes adjustable bracketmembers 38 and 40' having elongated adjustment slots 39 and 41respectively for receipt therethrough of clamping bolts 43. Anadjustment bolt 45 is suitably mounted through a protruding lug 47 onthe bracket member 38 for providing minute adjustments of the grindinghead inwardly and outwardly of the plane defined by the top of the wires18.

Speed transmission assembly The speed transmission assembly 34 fortransferring the rotational driving force of the drum 24 to the screwshaft 26 at a slight speed differential includes a gear transmissionassembly or system 46. Referring to FIG. 8, the gear system 46 includesa first spur gear 48 suitably connected to the driven drum 24 and asecond spur gear 50 suitably connected to the screw shaft 26 fortransfer of a rotational driving force thereto as received through thegear transmission system 46. The gears '48 and 50 are interconnected bya pair of spur gears 52 and 54 mounted in fixed relation for rotationtogether about a shaft 56. The gear 52 is operatively coupled to thegear 48 on the drum 24 by a nonmetallic idler gear 58. The spur gear 54is likewise operatively coupled to the spur gear 50 on the screw shaft26 by means of a second nonmetallic idler gear 60. In this manner, thedrum 24 drives the first gear 48 which in turn drives the idler gear 58for driving the spur gear 52. The spur gear 52 in turn imparts arotational driving force to the spur gear 54 for driving the idler 60which in turn drives the spur gear 50 and thereby the screw shaft 26.This new and novel arrangement of gearing allows for a simple andefficient gearing assembly for producing a very slight speeddifferential between the to tational speeds of the drum 24 and the shaft26.

The speed differential between the drum 24 and the shaft 26 is providedby employing gears in the transmission assembly 46 which vary slightlyin their circumferential dimension thereby producing slight andcontrollable speed variations between the various gears. As an example,the various spur gears 48, 50, 52, and 54 are designated in FIG. 7 ashaving a specific number of equal dimensioned teeth. The number of teethon a gear .is directly proportional to the circumference of that gear.Thus a gear with 6 teeth has a slightly larger circumference than a gearwith 55 teeth. In this manner when the gear 48 is driven at a certainspeed by the drum 24, the gear 52 being of a lesser circumference isthereby driven at a slightly greater speed providing a first stage speedincrease in the transmission assembly 46. The second stage speedincrease is then provided by the gear 54 which has a circumferenceslightly less than the circumference of the gear 52. It will be noted,however, that the gear 50 which is operatively connected to the shaft 26has a circumference slightly greater than the circumference of the gear54. This circumferential relationship between the gears 54 and 50provides a third stage speed decrease in the transmission system 46.Thus the gearing system 46 employs a three stage speed variabletransmission wherein various combinations may be employed for arrivingat a final rotational speed of the shaft 26 which is at a desired speedratio to the drum 24 to thereby accurately control the speed of traverseof the grinding head 22. Speed differentials may vary in any desiredmanner such as a first stage decrease, a second stage decrease, and athird stage increase or a first stage increase, a second stage decrease,and a third stage increase.

The speed of traverse of the grinding head may be calculated by thefollowing formula:

b0 T RP 1) In the above formula:

Thus using the example illustrated in FIG. 7 with R=500 P=1 /2, a=56,b=55, c=55, and d=54.

T=750 .00033 T=.2475 inch per minute Referring to FIGS. 9 to 11, thegear transmission system 46 is disposed in a housing or casing 62 havingfront and back plates 64 and 66 respectively. The plates 64 and 66define a pair of aligned apertures 68 and 70 respectively. The drum 24and shaft 26 are each received through a friction reducing member 71 inthe aperture 68 and mounted therein by a front bearing assembly 72. Thedrum 24 which is operatively coupled to the first spur gear 48 by a gearlock ring 74 terminates within the housing 62. The cross-threaded crewshaft 26, however, extends through the housing 62 and is receivedthrough a fric tion reducing member 75 in the aperture 70 in the backplate 66. The screw shaft 26 has a terminal end portion 76 suitablyshaped, as for example, a rectangular cross section, for the releasableengagement of a crank or the like for manual operation of the screwshaft 26. The second spur gear 50 is coupled to the screw shaft 26 by alock ring 78.

In the illustrated embodiment, the common shaft 56 about which the gears52 and 54 rotate in fixed relation is basically comprised of a gear stud80 suitably mounted to the front plate 64, and having a frictionreducing member 84 suitably mounted thereto and disposedcircumferentially of the stud 80 to provide a surface on which the gears52 and 54 are free to rotate. The gears 52 and 54 are locked in a fixedrelative position by means of a lock ring 86.

The idler gears 58 and 60 are suitably mounted to the housing 62 in acoupled relation to the gear pairs 48, 52 and 50, 54 respectively.Referring to FIG. 12, the idler gear 58 is conventionally mounted on anidler gear arm 86 by means of the bolt 88 which retains a gear stud 90on which the idler gear 58 rotates.

Referring to FIG. 11, the idler gear 60 is suitably mounted on an idlergear arm 92 by the bolt 94 which supports the idler stud 96 on which theidler gear 60 rotates. The idler arm 92 is mounted to the front plate 64for rotational movement to thereby pivot the idler gear 60 in and out ofcooperative engagement with the gears 50 and 54. In this manner, whenthe grinding assembly 20 is not in operation, the gear transmissionassembly 46 may be disengaged by pivoting the idler gear 60 to allow fora manual rotation of screw shaft 26 by a crank or the like. The idlerarm is fixed in a desired rotational position by the force exertedthereon by a spring 98 retained in position by a spring retainer arm 100which is suitably connected to the housing 62 by the bracket member 102.

This invention contemplates a flat driving means selectively operable todrive said card flats at any desired speeds including first speedsduring the carding operation and second speeds specifically for sidegrinding. The second speeds are greater than said first speeds tothereby facilitate the side grinding operation. In this manner, thisinvention has achieved the flexibility of operation wherein the wires 18may be side ground on their operative mounting on the carding machine 1even during the carding process or operation. Preferably, however, byshutting down the carding operation for a period of minimum duration,the wires 18 may be quickly side ground by driving the flats on theiroperative mountings on the carding machine 1 at said second speeds.Thus, the duration of the period of equipment down time for sidegrinding is considerably reduced by the capability of this invention togrind the wires 18 Without removal of the flats 16 from the cardingmachine 1.

Referring to FIG. 1, the flat card 10 is preferably driven incooperative relation with the carding cylinder or swift 8 in aconventional manner by a suitable power takeoff 104 from the main drivesystem 106 driven by a first motor 107 employed for operation of thecarding machine 1. A conventional gear train and removable belt assembly108 is employed in the power takeoff 104 whereby the speed of the flatcard 10 may be controlled and the flat card 10 may be disengaged fromthe drive system 106. Any other suitable disengageable transmission maybe substituted for the assembly 108.

Upon disengagement of power takeoff 104, the flat card 10 may then bedriven at a greater rate of speed by a second drive means for thespecific purpose of side grinding of the wires 18. As illustrated, thesecond drive means for the card flat 10 is the motor 30. The motor 30 ispreferably connected to a drive sprocket wheel 110 on the card flat 10by a suitable chain drive system 112 including a gear and clutchassembly 114. The

7 gear and clutch assembly 114 is employed to control the speed of theflat card and for disengagement of the drive system 112 when the powertakeoff 104 is operatively connected to the card flat 10 during thecarding operation.

Method of side grinding Referring to FIGS. 6 and 7, the progressivesteps of the method of side grinding of carding flats as the cardingflats are driven in their operative position on the carding machine isillustrated. Initially, the grinding head 22 is positioned relative tothe Wires 18 with each, of the plurality of abrasive discs 37 locatedbetween a pair of adjacent rows of flat wires respectively such that theopposed abrasive surfaces 39 on the discs 37 tend to abrade each of therows between which a disc 37 is disposed. Preferably, the outer edge ofthe discs 37 extend between the teeth about three quarters of thedistance between the top of the teeth and the bend or knee of the teethas shown in FIG. 6.

As the wire teeth 18 are moved past the grinding head 22 and thegrinding head 22 is traversed normally to the direction of movement ofthe flats, the abrasive member 37 bears against the wires and each, thewires and disc, tend to bend, as illustrated in FIG. 7b. However, it isundesirable and damaging to the teeth for the discs to pass from,through or past one row of teeth to the adjoining row while the disc ison any particular flat. Instead the discs are caused to pass from onerow to the next only in the space between the ends of the rows of teethon one flat and the opposing ends of the rows of teeth on the adjacentfiat.

Normally there is provided about one disc for every two to three rows ofteeth but this relationship may vary. The relationship between spacingof the discs and speed of traverse is random so that as the discs moveback and forth across the carding flats they ultimately effect theirgrinding action between all or nearly all of the rows. It is undesirableto obtain what is termed a patterned effect where only certain of thewires in each of the rows are side ground leaving numerous wiresuntouched even with repeated passage of the grinding head across theflats.

The speed of traverse of the grinding head 22 in relation to the speedof movement of the card flats 16 to cause the discs to pass from one rowof teeth to another only between the teeth on adjacent flats is criticalto provide the proper degree of side grinding of the wires 18 withoutcausing damage to the wires. If the grinding head is traversed at toogreat a rate, the discs will pass across the rows on individual flatsand the teeth 18 will be damaged. In prior art devices where grindingdiscs passed across the teeth, the discs could not extend anyappreciable distance between the teeth. Thus there was little or no sidegrinding and tapering of the teeth. There was only a minimal grinding ofthe top edge of the teeth.

In order to provide the desired grinding action, the abrasive members 37are preferably driven at a speed between 500 to 1700 revolutions perminute.

When the carding flats 16 are being operatively driven in cooperativerelation with the cylinder during the carding operation, the speed ofsaid flats is in the range of about 8 inches per minute to about 11inches per minute. In the aforestated situation, the grinding head ispreferably traversed at a speed less than about 4 inch per minute inorder to provide the desired movement of the abrasive members 37 throughthe rows of wires 18.

When the carding flats are being driven at an increased rate of speed bythe second drive means, illustrated as the motor 30, the flats 16 arepreferably moved at a rate of between about 10 feet per minute and about15 feet per minute. When the flats are being so propelled by the motor30, the desired rate of traverse may range from less than about inch perminute at a flat speed of about 10 feet per minute to about one inch perminute at a flat speed of about 15 feet per minute. It should berecognized,

however, that the flats 16 may be driven at any practical speed with theappropriate relation being developed between the flat speed and thespeed of traverse. Thus the traverse of the grinding head would varyfrom less than about 4 inch per minute at a flat speed of 11 inches perminute to about one inch per minute at a flat speed of about 15 feet perminute. It is contemplated that the mountings which are normallyemployed on carding machines for flat movement will not permit flatspeed in excess of about 30 feet per minute. Of course if flat speeds of30 feet per minute are employed, the speed of traverse of the grindinghead could be somewhat greater than one inch per minute.

The invention is not limited to the particular numerical relationshipswhich have been discussed. The important consideration is that the ratioof flat speed to grinder traverse speed be such as to achieve thedesired effect of grinding all of the rows of teeth on all of the flatswithout damage by causing the discs substantially never to pass acrossor through a particular row of teeth on a particular flat but to passfrom one row to another and in the open spaces between the teeth onadjoining flats.

Operation of the illustrated embodiment In the illustrated embodimentthe flats 10 and the side grinding assembly 20 are operatively driven orrotated by the motor 30 through the chain drive systems 32 and 112. Therotational drive force imparted to the drum 24 is transmitted to thescrew shaft 26 through the transmission system 34 in the mannerpreviously discussed to drive the screw shaft 26 at a slight speeddifferential from that of the drum 24. The thread follower 29 on thegrinding head extends through the keyway 28 and engages the crossthreads of the threaded screw shaft 26 to cause the head 22 totransverse the flats 16 by the effect of the differential movement ofthe shaft 26 and drum 24. By controlling the magnitude of the speeddifferential between the drum 24 and the shaft 26, the rate of traverseof the grinding head 22 may be accurately controlled. The control of themagnitude of the speed differential is effected by the speedtransmission assembly 46 in the manner previously discussed.

When the carding machine 1 is not in operation the power takeoff 104 tothe card flat 10 may be disconnected at the gear box 108 and the cardflat 10 operatively engaged to the motor 30 through the gear box 114 fordriving the card flat 10 at an increased rate of speed. In this mannerthe wires 18 may be more quickly side ground.

It is a distinct advantage to drive both the flats and the side grindingassembly by the same motor or otherwise have them preciselysynchronized. In this manner the proper speed relation may bemaintained. Further, the starting and stopping of the flats and sidegrinder are thus always simultaneous. Substantial damage to the teethmay result where such starting and stopping are not simultaneous.

It is to be understood that while we have illustrated and described oneform of our invention it is not to be limited to this specific form orarrangement of parts herein described and shown except insofar as suchlimitations are included in the claims.

We claim:

1. In a carding machine including a cylinder, a doffer, a plurality ofcard flats mounted on said machine for movement in an endless path incooperative relation to said cylinder and means for driving said cardflats, said flats having on their outer surfaces card clothing comprisedof a plurality of generally parallel spaced rows of wire teeth, saidrows of teeth extending generally in the direction of movement of saidflats with open spaces being provided between the ends of the rows ofteeth on adjacent flats, a grinding apparatus operatively mountedrelative to said flats for grinding of said teeth while said flats aredriven in their operative position on said carding machine comprising:

(a) a grinding head including a plurality of grinding discs eachdefining abrasive surfaces on the sides thereof, a portion of each ofsaid discs being located between a pair of adjacent rows of said teethand rotatable through a plane defined by the tops of said teeth, saidrotation causing the abrasive surfaces to effect a grinding action onthe sides of said teeth,

(b) means operatively connected to said grinding head for rotatablydriving said grinding head and for reciprocally moving said grindinghead across said flats transversely of said rows of teeth at a speedsufficiently slow related to the speed of movement of said flats suchthat the abrasive surface on each of said discs bears against the movingteeth of a particular row on a particular flat and substantially neverpasses across said row on that particular flat but passes from one rowto another row only in said open spaces between the teeth on adjoiningflats, said means for reciprocally moving said grinding head across saidflats includes:

(1) a frame member,

(2) a hollow drum rotatably mounted on said frame member and extendingacross said flats transversely of said rows, said drum defining a slotlongitudinally thereof for communication with its hollow interior,

(3) a cross-threaded screw shaft rotatably mounted in the hollow drum,said grinding head being slidably mounted on said drum and havingfollower means extending through said slot engaging the cross thread ofthe screw shaft, and

(4) transmission means operatively connecting the rotatable drum to thescrew shaft for transmitting a rotational drive between said drum andsaid shaft with a slight speed differential whereby the grinding head isdriven on said drum by said follower means at a desired speed while saidhead slides along said drum transversely of said rows, said transmissionmeans includes a gearing system comprised of a first gear meansoperatively mounted on said drum and driven therewith, a second gearmeans operatively connected to said screw shaft and driven therewith andthird and fourth gear means operatively coupled together and to saidfirst and second gear means respectively providing first, second andthird stage speed differentials between said first, third, fourth andsecond gearing means sequentially, two of said stages providing a speedincrease and decrease respectively and the other of said stagesproviding a speed differential in the same direction as one of the othertwo stages.

2. The apparatus as recited in claim 1 wherein said first and secondgear means are each spur gears having first and second circumferentialdimensions and said third and fourth gear means comprise third andfourth spur gears operatively coupled together and to said first andsecond gear means respectively wherein the gears in each of thefollowing pairs have slightly different circumferential dimension, saidfirst and third gears, said third and fourth gears, and said fourth andsecond gears, two of said paired gears providing a speed increase anddecrease respectively and the other pair of gears providing a speeddiflerential in the same direction as one of the other two pairs ofgears.

3. The apparatus as recited in claim 2 including means for mounting saidthird and fourth gears together for rotation in a fixed relation to eachother and wherein said first gear is coupled to said third gear by afirst idler gear and said fourth gear is coupled to said second gear bya second idler gear.

4. The apparatus as recited in claim 3 wherein one of said first andsecond idler gears includes releasable mounting means for retaining saididler gear in cooperative engagement in said transmission systemincluding means for moving said idler gear out of cooperative engagementto open the transmission means permitting manual operation of the screwshaft for manual placement of the grinder head relative to the rows ofteeth on the carding flats.

5. In a carding method employing a carding machine having a doifer, acylinder, flats movable in an endless path in cooperative relation withsaid cylinder, said flats having on their outer surfaces card clothingincluding a plurality of spaced rows of flexible wire teeth defining aplurality of passageways, said rows and passageways extending generallyin the direction of movement of the flats with open spaces beingprovided between the ends of the rows of teeth on adjacent flats, and arevolving grinding head in cooperative relation to said flats includinggrinding discs defining abrasive surfaces for said grinding the teeth onsaid flats including the steps of:

(a) moving the flats along said endless path about their operativemountings on the carding machine,

(b) locating a portion of each disc in respective passageways inengagement with the teeth of at least one of the rows of teeth definingsaid passageways and revolving said discs through a plane defined by thetops of said teeth to abrade the sides of said teeth,

(c) maintaining the discs in their respective passageways across atleast one of said flats, and

(d) passing said discs laterally to other passageways only when thediscs are in said open spaces between the ends of the rows of teeth onadjacent flats.

6. The method as recited in claim 5 wherein said flats are moved alongsaid endless path at a first speed and wherein said discs are movedlaterally of the movement path of said flats at a second speed, saidsecond speed being related to said first speed to move each discrespectively along a row of teeth on at least one flat to abrade theside of said teeth and to pass the respective discs to other passagewaysonly in the open spaces between the ends of the rows of teeth onadjacent flats.

7. The method as recited in claim 5 wherein each of said discs is passedthrough each of the open spaces between the ends of the rows of teeth onadjacent flats.

8. The method as recited in claim 5 wherein each of said discs is passedlaterally to the next adjacent passageway only in said open spacesbetween the teeth on adjoining flats.

9. The method as recited in claim 5 wherein each of said discs is passedlaterally to the next adjacent passageway at each of the open spacesbetween the teeth of each of the adjoining flats.

10. The method as recited in claim 5 wherein the flats are driven duringthe operation of the carding machine in cooperative relation with thecylinder and said grinding head is moved transversely of the rows ofteeth on the flats at a speed of less than about 4 inch per minute.

11. The method as recited in claim 5 wherein the cylinder is stationaryand the flats are driven separately from the carding machine at a speedin the range of about 10 feet per minute to about 15 feet per minute andsaid grinding head is moved transversely of said rows of teeth at aspeed from less than about /1 inch per minute at a flat speed of about10 feet per minute to about 1 inch per minute at a flat speed of about15 feet per minute.

12. The method as recited in claim 5 wherein the flats are driven at aspeed in the range of about 11 inches per minute to about 30 feet perminute and said grinding head is moved transversely of said rows ofwires at a speed varying from less than about inch per minute at a flatspeed of about 11 inches per minute to a speed slightly greater than 1inch per minute at a flat speed of about 30 feet per minute.

13. In a carding method employing a carding machine having a doffer, acylinder, flats movable in an endless path in cooperative relation withsaid cylinder, said flats having on their outer surfaces card clothingdefining a plurality of spaced rows of flexible wire teeth extendinggenerally in the direction of movement of the flats with open spacesbeing provided between the ends of the rows of teeth on adjacent flats,and a revolving grinding head in cooperative relation to said flatsincluding grinding discs defining abrasive surfaces for side grindingthe teeth on said flats including the steps of:

(a) moving the flats along said endless path about their operativemountings on the carding machine at a speed in the range of from about11 inches per minute to about thirty feet per minute;

(b) locating a portion of each disc between adjacent rows of said teethand revolving said discs through a plane defined by the tops of saidteeth; and

(c) moving said grinding head across said flats transversely of saidrows of teeth at a rate of speed varying from less than about A inch perminute at a flat speed of about 11 inches per minute to a speed slightlygreater than 1 inch per minute at a flat speed of about 30 feet perminute.

14. The method as recited in claim 13 wherein the cylinder is stationaryand the flats are driven separately from the carding machine at a speedin the range of about 10 feet per minute to about 15 feet per minute andsaid grinding head is moved transversely of said rows of teeth at aspeed from less than about inch per minute at a flat speed of about 10feet per minute to about 1 inch per minute at a flat speed of about 15feet per minute.

15. The method as recited in claim 13 wherein the flats are drivenduring the operation of the carding machine in cooperative relation withthe cylinder and said grinding head is moved transversely of the rows ofteeth on the flats at a speed of less than about A inch per minute.

References Cited UNITED STATES PATENTS 8/1938 Great Britain.

DORSEY NEWTON, Primary Examiner

